Design of XS₂ (X = W or Mo)‐Decorated VS₂ Hybrid Nano‐Architectures with Abundant Active Edge Sites for High‐Rate Asymmetric Supercapacitors and Hydrogen Evolution Reactions

Abstract

Two‐dimensional layered transition metal dichalcogenides have emerged as promising materials for supercapacitors and hydrogen evolution reaction (HER) applications. Herein, the molybdenum sulfide (MoS2)@vanadium sulfide (VS2) and tungsten sulfide (WS2)@VS2 hybrid nano‐architectures prepared via a facile one‐step hydrothermal approach is reported. Hierarchical hybrids lead to rich exposed active edge sites, tuned porous nanopetals‐decorated morphologies, and high intrinsic activity owing to the strong interfacial interaction between the two materials. Fabricated supercapacitors using MoS2@VS2 and WS2@VS2 electrodes exhibit high specific capacitances of 513 and 615 F g−1, respectively, at an applied current of 2.5 A g−1 by the three‐electrode configuration. The asymmetric device fabricated using WS2@VS2 electrode exhibits a high specific capacitance of 222 F g−1 at an applied current of 2.5 A g−1 with the specific energy of 52 Wh kg−1 at a specific power of 1 kW kg−1. For HER, the WS2@VS2 catalyst shows noble characteristics with an overpotential of 56 mV to yield 10 mA cm−2, a Tafel slope of 39 mV dec−1, and an exchange current density of 1.73 mA cm−2. In addition, density functional theory calculations are used to evaluate the durable heterostructure formation and adsorption of hydrogen atom on the various accessible sites of MoS2@VS2 and WS2@VS2 heterostructures.

Freestanding WS2-MWCNT Nanocomposite for Electrochemical Detection of Contaminants of Emerging Concern─Perfluorooctanoic Acid “A Forever Chemical” and Supercapacitor Applications

“…The schematic fabrication of the SSD with glowing LED is shown in the insetFigure E. However, our SSD’s cycling performance is comparable to that of other supercapacitor devices described in the sources included in Figure E. − The Nyquist plots (Figure F) were used to determine the solution charge conduction impedance, and after 10 000 cycles, there were no significant inconsistencies. The WS 2 -MWCNT device has an internal resistance ( R s ) of 2.3 Ω and charge transfer resistance ( R ct ) of 5.84 Ω before 10 000 cycles, which become 18.33 and 10.24 Ω, respectively, after 10 000 cycles.…”

Interfacial Interaction in NiFe LDH/NiS2/VS2 for Enhanced Electrocatalytic Water Splitting

“…The XPS survey of NiFe LDH/NiS 2 /VS 2 reveals the co-existence of Ni, Fe, V, O and S elements, which corresponds to the result of the EDS-mapping images. As revealed in Figure 3 a, the high-resolution XPS spectrum of V for VS 2 contains typical characteristic peaks at 514.12 and 521.62 eV, which can be related to the V 2+ 2p 3/2 and V 2+ 2p 1/2 , respectively [ 49 , 50 ]. Additionally, there are two dominant peaks at 516.87 and 524.10 eV that can be indexed to the V 4+ 2p 3/2 and V 4+ 2p 1/2 , respectively [ 49 , 50 , 51 ].…”

Constructing Hierarchical CoGa2O4–S@NiCo-LDH Core–Shell Heterostructures with Crystalline/Amorphous/Crystalline Heterointerfaces for Flexible Asymmetric Supercapacitors

“…13−17 Nevertheless, the rather low energy density of SCs precludes future deployment, and the possibility of addressing this issue directly points to the crucial component of SCs�electrode materials. 11,18,19 The key lies in how to judiciously design and construct complicated electrodes to overcome the bottleneck of SCs. 20 So far, battery-type electrode materials, such as metal hydroxides, metal sulfides, and metal oxides, have garnered a lot of interest from researchers owing to their high theoretical capacity.…”

“…Nowadays, the burgeoning industrial progress has led to the increasingly conspicuous emergence of environmental issues. − The need for energy conversion and storage technologies has skyrocketed as a result of the rapid development of green energy. − Many novel devices are being investigated for energy storage applications, including but not limited to lithium-ion batteries, , Ca/Al/Zn-ion batteries, ,,, supercapacitors, and so forth. Among them, supercapacitors (SCs) have received a lot of interest as potential future energy storage devices due to impressive specific capacitance, exceptional cycling stability, high power density, cost-effectiveness, and environmental friendliness, showing great promise for renewable energy. − Nevertheless, the rather low energy density of SCs precludes future deployment, and the possibility of addressing this issue directly points to the crucial component of SCselectrode materials. ,, The key lies in how to judiciously design and construct complicated electrodes to overcome the bottleneck of SCs …”